Backport fixes and enable new Dagger Validations

This corrects a duplicated binding of UnfoldTransitionModule
which will become an error in future Dagger releases. With
this change, the checks are also raised to error to prevent
further regressions:

dagger.explicitBindingConflictsWithInject=ERROR
dagger.strictMultibindingValidation=enabled

This change unblocks an upgrade of external/dagger2

Test: m SystemUI-core; compiles without error
Test: Treehugger presubmit
Flag: NA (backport of a fix from internal main)
Change-Id: I7a887cf6ac200a9080893dd4dde969aef7ceef5b
Merged-In: I0aef5464000d30b27097ddaed9548d128bedccf6